It was a Thursday, the fourth day of August, 2011, and I was sitting at breakfast with my wife Maisie. Maisie is an archaeologist who, like me, specialises in Britain’s prehistoric (i.e. pre-Roman) past; so she understands what I have to do when I head out on a Time Team shoot. As she sipped her coffee she was looking through the Call Sheet of the shoot I’d be leaving for later that day. Every shoot has a Call Sheet which takes Production a long time to produce, so we’re all supposed to read them closely. They give details of Health and Safety hazards, local emergency services, and stuff about the hotel we’d be staying at – not to mention other important things, like where to get a decent pint of beer in the evening. As normal, I’d checked details of train times, the hotel and local pubs, but I have to confess I hadn’t even glanced at the Health and Safety stuff. Silly me.

‘I didn’t think you had much of a head for heights?’ She asked, all innocence.

‘I don’t,’ I replied, chewing on a slice of toast and Maisie’s excellent home-made marmalade.

‘That’s a shame…’

‘Why?’ I asked this without thinking what I was saying – a sort of reflex while I lingered over the last bit of marmalade.

‘Oh,’ she replied, again all innocently ‘it’s just that it says here there’s a sixty metre drop down to sharp rocks and the sea at High Tide…’

Gateholm Island from the mainland. I took this photo a week before we began filming when we recce’d the site.

‘Whaaaat?’ I grabbed the Call Sheet from her. She was right. I’d known full well that the site was an island off the Pembrokeshire coast, but I’d only seen air photos and they never give an accurate impression of surface features, such as the rise and fall of the land. This island was in precipitous rocky country and the only safe way to get across to it was by a zip-wire. Living in the Fens I don’t have very much to do with mountains or rock climbing. In fact weeks can pass and I never have to climb anything higher than the stairs to our bedroom on the first floor. So a sixty metre drop came as a horrible surprise.

Then I read the specification closely. The zip-wire would be erected and operated by professional mountaineers and would cross a gap of about 250 metres between the island and the mainland. We’d have to wear a harness and hard hat. And say our prayers, they should have added.

Phil Harding on the morning of Day 2. Phil’s site was safely on dry land and he didn’t have to use the zip-wire. That’s why he’s so happy.

Anyhow, it’s odd they way you forget about things you don’t want to think about. SO I got in the train at Peterborough and trundled across England, then into Wales and on, and on, to the extreme south-western corner of Pembrokeshire. It was a delightful run. The hotel was excellent and breakfast was delicious. I stuffed myself.

After breakfast I drove down to the site with Tim Taylor, the Series Producer and the man who invented the Time Team format. Tim was on fine form and skylarks were singing as we drove down the narrow lane to the Incident Room in some farm buildings. I had another coffee and chatted amiably to various cameramen, sound recordists and one or two other archaeologists, all of whom seemed completely relaxed. They should have been. None of them were going to be working on the island.

The zip-wire to Gateholm Island can be seen behind Kerry Ely who is checking that we are all safely harnessed-up.

Then I got a lift down to the zip wire, where I met up with Matt Williams and Raksha Dave, the two principal archaeologists I’d be working with. They seemed a bit quieter than usual, but otherwise relaxed. We all climbed into our harnesses and headed down to the launch point, a journey that required us to be roped to a landline, and took us about ten minutes. The zip-wire launch point was horribly exposed and there was a very stiff breeze blowing off the sea. Kerry Ely, another archaeologist, but also the man in charge of all site installations, was waiting for us. He gave a friendly smile, as if to say, what a lovely day to throw oneself off a cliff and out into a howling gale. But then Kerry’s pre-Time Team life was with the Forces and danger never seemed to bother him, even slightly. While we watched, he hitched his harness onto the land-line and almost casually stepped off the edge of the cliff, as if nipping across the street for a packet of fags. Then he vanished from sight, only to reappear fifty metres out, dangling perilously high above the foaming breakers and heading for the island, where two other mountaineers were pulling him in. Then he waved to us in a cheery sort of fashion – with both hands. I gulped. It was terrifying.

‘Who’s going next?’ It was Trevor, the immensely fit professional mountaineer who ran the zip-wire. Raksha, always polite pointed at me.

‘Age before beauty…’ She smiled. I smiled back grimly. I could have killed her.

‘After you, Professor…’ Matt said. Damn him.

I felt like a condemned man having his head shaved before the electric chair, as Trevor carefully checked my harness. I hoped he’d find a bad knot, or even better, something that couldn’t be fixed. But it was not to be. He stepped back. Again, I couldn’t help thinking about the executioner at the electric chair; like him, Trevor didn’t want to get a shock, or be dragged down to oblivion…

‘Are you ready?’ He asked casually, as if he was about to offer me a mug of hot tea.

I managed a weak nod of the head.

I knew I mustn’t look down, but I could hear the breakers crashing against the cliffs far below. I was also aware that Raksha and Matt were looking on. Some degree of cool must be maintained at such moments. At least, I thought, they could say I had hurtled to my death with a smile on my lips, if not with a song in my heart.

So I did it. I stepped out into the void. Suddenly the wind seemed to blow me apart. For an instant I thought I’d come off the blessed wire, but then I detected the pulley’s high-pitched scream directly above me. Thank God, I was still attached. As I plummeted downwards I could feel the harness between my legs getting tighter and tighter. I bitterly regretted eating so much for breakfast. But that pain took my mind off things. I pulled even harder on the rope to relieve the pressure. That sort of worked. But by then my fears were beginning to pass. I’d survived.

Strangely, I now don’t have such a fear of heights. I did that trip another half-dozen times and by the end I even managed a very quick two-handed wave.

At the end of day 2 we were treated to a meal of Iron Age food, including rock samphire. I’m used to the sort of samphire which grows in the muds around the shores of the Wash. That stuff is delicious. This stuff, though, tasted of raw seaweed and salt water. Horrible!